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weston.pace
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Homework Statement
Special Relativity A.P French Problem 1-9
An eccentric billionaire decides to sterilize his 106 liter swimming pool by boiling the water in it. For heating purposes he uses the fusion reaction:
1H + 3H → 4He + radiant energy
Assuming the heating system is 20% efficient, how much does he pay for the tritium (3H) to raise the pool temperature from 20°C to 100°C? It takes 4.2 joules to raise 1g of water through 1°C. Tritium costs about $5 per cm3 of gas at STP.
Homework Equations
E = mc2
The Attempt at a Solution
Total energy required:
[tex] E_{total} = 4.2 \frac{J}{g°C} * 10^9 g * 80°C = 3.36*10^{11} J[/tex]
Energy Generated per reaction:
[tex] E_{reaction} = m_{diff} * c^{2}[/tex]
[tex] E_{reaction} = ((1.0081 + 3.0170) - 4.0039)amu * 1.6603*10^{-27} * (3*10^{8}\frac{m}{s})^{2} = 3.1682 * 10^{-12} J [/tex]
Atoms per cubic centimeter of gas at STP:
[tex]\frac{atoms}{cm^3}=6.0221*10^{23} * \frac{1}{22.711} * 10^{-3} = 2.6516 * 10^{19}[/tex]
Final Result (1/0.2) is to account for 20% efficiency:
[tex]cost=$5*\frac{1}{0.2} * \frac{E_{total}}{\frac{E_{reaction}}{\frac{atoms}{cm^3}}} =~ $100,000[/tex]
The answer in the book is $50,000, which would imply I'm off by a factor of two. I've looked over this for some time and can't see my mistake. Can anyone help me spot what I've missed?
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